Spinal disorders such as degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, scoliosis and other curvature abnormalities, kyphosis, tumor, and fracture may result from factors including trauma, disease and degenerative conditions caused by injury and aging. Spinal disorders typically result in symptoms including pain, nerve damage, and partial or complete loss of mobility. For example, after a disc collapse, severe pain and discomfort can occur due to the pressure exerted on nerves and the spinal column. In another example, disorders of the sacroiliac joint can cause low back and radiating buttock and leg pain in patients.
Various pathologies of the human spine may be treated by stabilizing and properly positioning the vertebrae and joints of the spine. Some spinal implant assemblies rely on one or more rods as structural support for stabilizing and properly positioning components of the spine. Vertebral anchors such as bolts, screws, and hooks are typically secured to the vertebrae for connection to the one or more rods. These vertebral anchors must be positioned at various angles relative to the one or more rods to accommodate the anatomical structure of a patient, the physiological problem being treated, and the preference of the physician. It is difficult to provide secure connections between spinal support rods and vertebral anchors at the various angles that may be required, especially where there are different distances between rods and bolts and where components are located at different relative heights within the patient.
Spinal implants can be engaged to or along one or more vertebrae of the spinal column for the treatment of various spinal conditions or abnormalities. Elongate rods are commonly used to stabilize and support portions of the spinal column for treatment, either by fixing the spinal column or by permitting at least some degree of relative motion between the stabilized motion segments. Bone fasteners such as, for example, vertebral screws are provided to secure the elongate rods to one or more vertebrae at a particular location along the spinal column. In some instances, connectors or other types of coupling devices are used to interconnect the rods with the bone fasteners. Current connectors and coupling devices typically have a large footprint or outer profile, including numerous pieces that are not particularly easy to use or assemble, and/or are not sufficiently adjustable to accommodate for variations in the position and/or angular orientation of the bone fasteners (e.g., vertebral screws) relative to the elongate rods.
In some spinal implant assemblies, each bone fastener (e.g., vertebral screw) can be coupled to the rod with a connector. The connector attaches to a portion of a bone fastener and attaches to the rod.
Surgical treatment of spinal disorders includes fusion, fixation, discectomy, laminectomy and implantable prosthetics. During surgical treatment, one or more rods may be attached via fasteners to the exterior of two or more vertebral members. Fasteners may also be attached to iliac bone. Iliac connectors, also called lateral connectors, are used to connect iliac screws to a spinal rod. Seating the rod into these connectors can be difficult because, among other things, the angle between the rod and the connector is typically not 90 degrees, which requires that the rod be bent by the surgeon to conform it to the particular angle needed for treatment of the spinal disorder.
It would therefore be desirable to provide a spinal implant assembly having a connector configured to lock into the appropriate position at different angles in the coronal plane of the spine. Thus, there is a need for a spinal connector assembly that provides advantages over existing connector or coupling devices.